Albuminuria as a marker of arterial stiffness in chronic kidney disease patients.

AIM: To access the association between albuminuria levels and arterial stiffness in non-diabetic patients with hypertension and chronic kidney disease (CKD) stages 1-2, treated with renin angiotensin blockade agents plus other hypertensive drugs when needed.

METHODS: One hundred fifteen patients [median age 52 years (68% males)] were consequently enrolled in the study. For each patient, we recorded gender, age, body mass index (BMI), peripheral systolic blood pressure (pSBP), peripheral diastolic blood pressure, peripheral pulse pressure, central systolic blood pressure (cSBP), central diastolic blood pressure (cDBP), central pulse pressure (cPP), hematocrit, hemoglobin, hsCRP, total cholesterol triglycerides, high-density lipoprotein-C, low-density lipoprotein-C, calcium, phosphorus, parathormone, and albumin, as well as 24 h urine albumin excretion. According to 24-h urine albumin collection, patients were then classified as those with moderately increased albuminuria (formerly called macroalbuminuria) (≤ 300 mg/d) and those with severely increased albuminuria (formerly called macroaluminuria (> 300 mg/d). We considered aortic stiffness (AS) indices [carotid femoral pulse wave velocity (PWVc-f) and augmentation index (AIx)] as primary outcomes of the study. We explored potential correlations between severely increased albuminuria and AS indices using a multiple linear regression model.

RESULTS: Fifty-eight patients were included in the moderately increased albuminuria group and 57 in the severely increased albuminuria. Blood pressure measurements of the study population were 138 ± 14/82 ± 1.3 mmHg (systolic/diastolic). There were no significant differences in age, sex, and BP measurements between the two groups. Patients with severely increased albuminuria had higher PWV and AIx than patients with moderately increased albuminuria (P < 0.02, P < 0.004, respectively). In addition these patients exhibited higher BMI (P < 0.03), hsCRP (P < 0.001), and fibrinogen levels (P < 0.02) compared to patients with moderately increased albuminuria. In multivariate linear regression analysis, severely increased albuminuria (β = 1.038, P < 0.010) pSBP (β = 0.028, P < 0.034) and Ht (β = 0.171, P = 0.001) remained independent determinants of the increased PWVc-f. Similarly, severely increased albuminuria (β = 4.385, P < 0.012), cSBP (β = 0.242, P < 0.001), cPP (β = 0.147, P < 0.01) and Ht levels (β = 0.591, P < 0.013) remained independent determinants of increased AIx.

CONCLUSION: These findings demonstrate an independent association between AS indices and severely increased albuminuria in non-diabetic, hypertensive patients with CKD stages 1-2 treated with renin angiotensin aldosterone system blockers.